Most manufacturers and suppliers of Epsom salts recommend adding two cupfuls (around 500g) of salts into a warm bath, before soaking for around 20 minutes. However, if you accidentally pour in more than this, it won't do you any damage: recent research shows your skin is unlikely to absorb enough magnesium to cause harm. Instead, incidences of magnesium overdose tend only to occur when people ingest Epsom salts, with symptoms including nausea and headaches. Should you rinse off an Epsom salt bath? Epsom salts can be dissolved in a warm bath, in the hope of aiding its relaxation and therapeutic properties. Whether you're a fan of ice baths or warm baths, there's nothing better than a good soak to help tired muscles recover after a run or race. But what about Epsom salts – are they worth the investment? What is an Epsom salt bath? Epsom salts have long been purported to offer relief from a variety of ailments and symptoms, including: Epsom salt is made of magnesium and sulphate,' says Corinne Croce, D.P.T, co-founder of Body Evolved, a boutique physical therapy studio in New York City. ' Magnesium is known to increase relaxation, reduce inflammation, and aid in muscle and nerve function, while the sulphate in Epsom salt is said to help with recovery and detoxification.'